With improvements of the communication technology and the electronic technology, the electronic devices equipped with various functions, such as cell phones allowing worldwide people to communicate with each other, Walkman allowing people to listen music anytime and anywhere, personal computers assisting people to process many things, etc., have become necessary tools for modern persons. In addition, a variety of electronic devices can be combined integratedly, so the functions of using cell phone to listen music or using the personal computer to dial are implemented gradually.
The electronic devices are provided with thousands and thousands of precise electric devices, so during usage the electronic device must be protected from being short circuit due to contacting with water, or being damaged by affected with damp. Connection ports on the electronic device for connecting external devices are portions which are penetrated by moisture most easily. Some manufacturers mount a waterproof stopper on the connector or mount a waterproof washer inside the connector to stop penetration of moisture, however, usage of the waterproof stopper or the waterproof washer has problems of difficult assembly, too high cost, and being hardly applied to the connector with special standard. Please refer to FIG. 1 which shows a metal casing 11 of a connector compatible to the Micro USB standard. In order to keep the drawing simple, some elements such as a tongue plate and connection terminals inside the metal casing are not shown in the FIG. 1. The Micro USB connector is mainly adapted for a slim type electronic device, such as smart phone, a tablet computer, etc. In order to ensure the external plug 12 to steady transmit data during being inserted into a connector, the metal casing 11 is provided with two openings 110, and the external plug is provided with two hooks 121 correspondingly. When the external plug 12 is inserted into the Micro USB connector, the hooks 121 can hook the openings 110 to ensure the connection stability.
The openings 110 can ensure the connection strength of the Micro USB connector, but also generate a loophole for whole waterproof scheme. Therefore, if the manufacturer designs the Micro USB connector with the waterproof function, a metal plate must be soldered on a top surface of the metal casing 11 and a waterproof washer must be further mounted inside the metal casing 11 for ensuring the completeness of waterproof function. However, such design seriously impairs production and assembly speed of the connector, and efficiently improves manufacturing cost, so it is not an ideal design. Therefore, what is needed is to develop a new structure of waterproof connector which does not need waterproof stopper or waterproof washer and can be applied to the slim type special connector, so as to solve problems that the traditional connector has too high manufacturing cost and is not easy to be assembled.